Due to advantages such as high hardness, transmittance of broadband light, chemical stability, high thermal conductivity, low thermal expansion, electrical insulating properties, biocompatibility, and eco-friendliness, nano-diamond is applicable in a variety of industrial fields such as the electronic, chemical, and medical industries. Synthetic diamond powder having a size of micrometers has been widely used in many industries.
With recent breakthroughs in nanotechnology, research into nano-diamond having a very small particle diameter has been conducted. Nano-diamond particles having an average particle diameter of from about 5 nm to about 10 nm may be obtained in a very short explosion time under an extremely high pressure
Nano-diamond particles prepared to have an average particle diameter of from about 5 nm to about 10 nm are nano-diamond aggregations with surfaces covered with a disordered graphite layer. These nano-diamond particle aggregations may have a variety of chemical and structural characteristics depending on a chemical treatment method.
Nano-diamond has unique electrical, chemical, and optical characteristics, such as small particle size, large surface area, high mechanical strength, and adjustable surface activity. However, nano-diamond particles tend to form aggregations due to increased attraction between particles resulting from a large surface area, and thus there is a limit to prepare nano-diamond having a particle diameter of tens of nanometers or less.